FOSSA is described as 'Offers automated license scanning, dependency analysis and reports at each commit. Get a process up an running in 60 seconds, without slowing down development' and is a vulnerability scanner in the security & privacy category. There are more than 10 alternatives to FOSSA, not only websites but also apps for a variety of platforms, including Linux, Windows, Mac and Self-Hosted apps. The best FOSSA alternative is HarborGuard. It's not free, so if you're looking for a free alternative, you could try HarborGuard or Mend Renovate. Other great sites and apps similar to FOSSA are spdx-tool, ScanCode, Black Duck Software and Mend Bolt.